Only yesterday I was thinking how quiet it was on this list without the
prickly Cereoid

What you are saying is that the fruits of Cactaceae are closer to pomes
(apples) than berries?
PvR

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Cereoid+10 schreef
Not exactly.

Most references describe Cactus fruit as berries but technically they are
not. The fruit of Cactaceae are actually modified receptacles. In the genus
Opuntia, the receptacle is typically sunken into a modified branch. In most
In many Cactus genera, the fruit are covered with scales and/or spines from
areoles. Only in the most advanced genera such as Mammillaria and Melocactus
are the fruit completely naked, fleshy and indistinguishable from berries.

Areoles are axillary buds that contain trichomes rather than bud scales.
Besides the Cactaceae, areoles can be found in the Portulacaceae and
Didieraceae.

What really distinguishes the Cactaceae is the floral parts being spirally
arranged with the leaves grading into bracts and sepaloid and petaloid
tepals. In most flowering plant families, the floral parts are whorled.

Spines are modified leaves and/or leaf parts and can be found in a number
of unrelated plant families.

Jie-san Laushi wrote
Floral and fruit characteristics are high in importance. Occasionally
other features are used, too. For instance, the family Cactaceae is
characterised by flowers with numerous petals, sepals, and anthers (certain
other families may have either only 4 or only 5 petals), fleshy fruits
(berries, I believe?), and areoles -- that is, the "tufts" or clusters of
spines. The areoles are one key feature for telling true cacti from spiny,
cactus-like succulents of other families, whose spines tend to occur singly.
Of course, when they flower, the differences are even more visible.

Jie-san Laushi

Huodau lau, xuedau lau, hai you sanfen xue bulai

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Because I am limited (?) by the logic of a Computer Science education,
what do you bio-types use for classification criteria??